Setting the WDM_READ bit in wdm_disconnect() is useless, as wdm_disconnect()
won't be called at all as long as wdm_read() is blocking waiting for this bit.
Use wait_event_interruptible_timeout for blocking reads to allow the USB
subsystem to call wdm_disconnect, and thereby allow a blocking read to
complete on device removal.
Without this, a blocking read will prevent a device from being removed.
Signed-off-by: Bjørn Mork <bjorn@xxxxxxx>
---
drivers/usb/class/cdc-wdm.c | 19 +++++++++++--------
1 files changed, 11 insertions(+), 8 deletions(-)
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 023d271..88fee93 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -419,14 +419,18 @@ retry:
}
rv = 0;
} else {
- rv = wait_event_interruptible(desc->wait,
- test_bit(WDM_READ, &desc->flags));
- }
+wait:
+ rv = wait_event_interruptible_timeout(desc->wait,
+ test_bit(WDM_READ, &desc->flags), 100);
+ /* may have happened while we slept */
+ if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
+ rv = -ENODEV;
+ goto err;
+ }
- /* may have happened while we slept */
- if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
- rv = -ENODEV;
- goto err;
+ /* timed out? */
+ if (!rv)
+ goto wait;
}
usb_mark_last_busy(interface_to_usbdev(desc->intf));
if (rv < 0) {
@@ -782,7 +786,6 @@ static void wdm_disconnect(struct usb_interface *intf)
/* the spinlock makes sure no new urbs are generated in the callbacks */
spin_lock_irqsave(&desc->iuspin, flags);
set_bit(WDM_DISCONNECTING, &desc->flags);
- set_bit(WDM_READ, &desc->flags);
/* to terminate pending flushes */
clear_bit(WDM_IN_USE, &desc->flags);
spin_unlock_irqrestore(&desc->iuspin, flags);
--
1.7.8.3
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